Circuit-breaker.



R, R. DUNLOPK CIRCUIT BREAKER.

APPLICATION FILED SEPT.23,1910.

Patented Jan. 19, 1915.

W f/T/9j% W @Hiomtu THE NORRIS PETERS CQ. PHOTOLITHQ, WASHINGTONv D. C

UNITED STATES PATENT orrrcn.

ROBERT E. DUNLOIP, OF COLUMBUS, OHIO, ASSIGNOR TO THE JEFFREY MANUFACTURING COMPANY, A CORPORATION BF OHIO.

CIRCUIT-BREAKER.

Application filed September 23, 1910.

To all whom it may concern Be it known that I, ROBERT R. DUNLOP, a citizen of the United States, residing at Columbus, in the county of Franklin and State of Ohio, have invented certain new and useful Improvements in Circuit- Breakers, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to improvements 1n circuit breakers, and more particularly to circuit breakers adapted for use on mine or similar locomotives. It will be readily apparent, however, that circuit breakers embodying my invention are equally adapted for use in other connections.

One of the objects or my invention is to produce a circuit breaker which, when used in connection with a properly designed starting box, will be automatically closed when the starting box lever is thrown to ott' position.

Another object of my invention is to provide automatically controlled means for opening and closing the circuit, the said means being auxiliary to the main controlling solenoid.

A still further object is to provide a circuit breaker which may be entirely inclosed in a tight casing through which no movable mechanical elements such as rods or levers extend.

In Figure l of the accompanying drawing which forms a part of this specification, I have shown diagrammatically a circuit breaker embodying my invention and also a starting box in combination with it. The casings for the circuit breaker and the starting box are shown in cross section. Fig. 2 is an enlarged detail view of certain starting box parts.

Referring to the drawings, 1 represents a locomotive having a trolley 2 which engages with a supply wire 3.

4 represents the casing for the circuit breaker and may be considered to be gastight in order to prevent the inflow of explosive gases should the locomotive move to regions where such gases exist. It Wlll. be understood, of course, that the casing 4c is mounted at a suitable point on the locomotive and that it is shown separated therefrom merely for clearness of illustration. Within the casing 4. is mounted the main controlling solenoid 5 to which is led the Specification of Letters Patent.

Patented Jan. 19, 1915.

Serial No. 583,;61.

main current fpom the controller through the conductor 6. The other end of the solenoid terminates in the forked terminal 7, a similar forked terminal 8 being provided at another point in the casing. From the terminal 8 a conductor 9 leads to the starting box 10 which is also provided with a closed casing and which is also mounted on the locomotive, although shown separated therefrom for purposes of clearer illustration.

The starting box 10 may be of any preferred construction. I have shown, however, a starting box having a lever 11 with which the conductor 9 connects, the other end of the lever 11 being adapted to engage the contact points 12, 12, which are connected together by means of resistances 13, 13. When the lever is moved from the position shown in full lines to the position shown in dotted lines, the circuit is gradually established through the resistances 13, 13 to the conductor wire 14 which supplies the motor 15. When in the position shown in full lines no current passes through the motor.

A switch blade 16 adapted to engage with and connect the contacts 7 and 8 is mounted upon the slidable core 17. This core is so mounted that its ends extend into the solenoids 18 and 19. The solenoid 18 is connected into a shunt of the main circuit, one end of the shunt being connected preferably to the end of the conductor 6, and the other being connected to an auxiliary contact point 20 of the starting box. A second auxiliary contact point 21 is also provided and is connected with the first main contact point 12 by means of a conductor 22. The lever 11 is provided with an auxiliary contact plate 11 insulated from the lever proper, and this plate serves to connect the contact plates 20 and 21 when the lever is in off position and thus establish connection through the solenoid 18. When the solenoid is thus energized, it tends to move the core 17 in a direction to engage the switch blade 16 with the contacts 7 and 8 if it is not already so engaged.

The main solenoid 5 is provided with a movable core 23 which carries a contact point 24 electrically connected with the main conductor 6. X hen the current through the solenoid 5 exceeds a certain predetermined amount the core 23 is lifted or moved against the action of a spring as may be preferred solenoid 18.

and connection is established by means of the contact point 24, the contact 25 and the conductors 2,6 and 27 through the solenoid 19. When the solenoid 19 is energized it immediately moves the core 17 and the switch blade 16 in a direction to break the connection between the switch blade and the contact points 7 and 8, thus breaking the main circuit. As soon as the circuit is broken the solenoid 5 is deenergized and the contacts 24 and 25 separate, thus breaking the auxiliary circuit through the solenoid 19 and leaving the core 17 free to be moved by the The main circuit remains broken until the starting box lever 11 is thrown to ofl position, when the solenoid 18 is energized and the circuit through the circuit breaker closed automatically.

1t will be noted that I have provided automatic means for closing the circuit breaker, and also that the automatic means is so related to the starting box that it is impossible to close the circuit through the circuit breaker when the starting box lever is in position to establish connection through the motor.

What 1 claim is The combination with a main circuit switch, of an electro-magnetic means for" actuating the switch to open the circuit, an electro-magnetic means for actuating the switch to close the circuit, a second switch for controlling the supply of current to the first electro-magnetic actuating means, an electromagnetic device connected with the main circuit for closing the said second switch when the main circuit is overloaded whereby the main switch is moved to open the circuit, a third manually controllable switch for opening and closing the main cir-' cuit, and means associated with the said third switch for controlling the second electromagnetic actuating means to cause it to close the first main switch whenever the third manually controllable switch is open.

In testimony whereof I afiix my signature, in presence of two witnesses.

ROBERT R. DUNLOP.

Witnesses:

ALICE A. Tmnn, M. I. BREWER.

Copies of this patent may be obtained for five cents each, by addressing the Gbmmissione'r of ra tentlg Washington, D. 0. 

